Density-dependent growth is important for maturation dynamics
A new modelling study, published in PNAS, shows that density-dependent growth is important for understanding maturation dynamics in Northeast Arctic cod.
Northeast Arctic cod shows a major decline in its average age at first spawning, starting from 1930s and continuing to the present day. The importance of demographic truncation, plasticity, and evolutionary adaptation for this pattern continues to be debated. A new modelling study, published in PNAS, sheds some light on this discussion. The results turn out to be sensitive to the assumed density dependence in growth: if this is weak, then evolutionary adaptations are essential. However, if density dependence is strong, then much of the change in maturation can be explained through growth-mediated phenotypic plasticity.
Eikeset, A. M., E. S. Dunlop, M. Heino, G. O. Storvik, N. C. Stenseth, and U. Dieckmann. 2016. Roles of density-dependent growth and life history evolution in accounting for fisheries-induced trait changes. Proceedings of the National Academy of Sciences of the United States of America 113:15030–15035. doi:10.1073/pnas.1525749113. Open access!